Trends in Use of Biotic Resources (DP IB Geography)

What are Biotic Resources?

Biotic resources

• Biotic resources are living resources

• In oceans biotic resources include small phytoplankton, fishes, crustaceans, mammals and any other living creature beneath the ocean’s depths

Uses of biotic resources

• Fish and shellfish are the main constituents of diets across the world:

  • Food thickeners contain sea algae

  • Shampoos, creams and other cosmetics contain seaweed

• Phytoplankton is vital for oxygen production in the air that we breathe

• Medicines for all sorts of diseases contain chemicals from plants and animals in the ocean 

Trends in Use of Biotic Resources

• The use of biotic resources is increasing

• Increasing demand for biotic resources and the improvement of fishing technologies put pressure on the ocean environment 

• With unsustainable fishing practices, global fishing stocks are depleting

Overfishing

• Overfishing involves catching so many species that the repopulation rate can’t keep up. This causes fish populations to deplete 

• Valuable fishes like cod are in decline, whilst others are endangered or even extinct 

• Drift nets are huge nets that move along the ocean, attached to floats on the ocean surface 

• Seine nets operate from the coastline or boats. Large nets hang downwards, weighted at the bottom and connected to floats at the top 

• Traps and pots line the seabed, ideal for catching crustaceans  

• Long-line fishing involves a long line of wire (50–100km) with hooks attached. They can catch plenty of fish near the ocean surface

• Bycatch

  • Fishing nets are huge, typically used for commercial fishing in large quantities

  • A net used to catch small creatures, like shrimps, catches all sorts of other marine life, like turtles, dolphins or other fishes

  • Fishermen throw these “spare” dead animals back into the oceans

  • In some cases, bycatch can be larger than the overall net catch

• Fish aggregating devices (FADs)

  • FADs offer shelter for fish from other predators 

  • They are used to attract fish to an area, where nets then catch the fish

  • They can be technologised beacons or just pieces of wood

Habitat destruction and pollution

• Bottom trawling involves dragging nets along the ocean floor

• This can damage the seafloor and other marine areas, including reefs

• Dragging heavy nets along the bottom of the ocean will pull up plant roots and disturb sediment

• Dynamite baits and poison are also destructive fishing techniques 

• Fishing industries leave behind ghost gear, like nets, ropes and traps. This contributes to large percentages of plastic pollution

• This discarded material can still trap marine life and damage ecosystems

Overfishing of our oceans 

Alternatives to Overfishing

Aquaculture

• Aquaculture is a useful alternative to overfishing

• Aquaculture is the farming of fish, crustaceans and marine plants in a controlled environment

• It is a viable modern innovation for aquatic seafood production

• It is a solution to counter the effects of mass overfishing and to increase yields to feed the population and reduce food insecurity

• Aquaculture is now one of the leading industries in food production 

• However, there are concerns about pollution, deforestation, mangrove clearing and disease spread

• Some examples of aquaculture include: 

  • Pond systems – artificial enclosed ponds to rear marine life like shellfish 

  • Open net pens – man-made mesh enclosures floating on water bodies to rear fish 

  • Submersible net pens – underwater cages to rear fish

  • Recirculating systems – indoor pond tanks with a water circulating system. The system moves waste water out, purifies it and reintroduces it back into the pond

The growth of aquaculture

Sustainable fishing and conservation

• Sustainable fishing alternatives are vital for combatting overfishing, whilst also ensuring there is enough aquatic life in the future

• Getting involved on an individual level:

  • We can make better dietary choices like reducing seafood, choosing sustainably sourced seafood and minimising food waste

  • We can educate ourselves and others about the fishing industry and sustainability 

• Timed fishing

  • Traditional fishing techniques by Indigenous People involve fishing at certain times of the year, historically managed by the tides and moon

  • Fishing at specific times of the year allows fish stock replenishment

  • In some areas, fishing is banned 

• Sustainable technologies

  • Traditional techniques can ensure direct catch with no risk of bycatch 

  • Reel and rod fishing has developed from traditional hook-and-line. It minimises the amount of fish caught in one go and bycatch returns to the ocean quickly

  • Modern spearfishing guns mirror traditional spearfishing techniques, catching one fish at a time

  • Floating fish traps are nets held in place by anchors. Fish are “caught” without getting dangerously entangled. Any bycatch can be easily released 

• Monitoring overfishing 

  • Cameras attached to boats track fishing levels

  • Remote Electronic Monitoring helps to collect data about marine activity  

• Managing fisheries 

  • People at all levels work to manage fisheries

  • Many stakeholders value oceans differently, like fishermen, conservationists, and consumers

  • International agreements provide fishing laws to protect the oceans and reduce illegal fishing

• Conservation areas 

  • Marine protected areas have particular restrictions on fishing activity, such as gear restrictions, fish species restrictions, and access restrictions

  • No-take zones are no-use areas, not just for fishing, but also for mining and other activities 

  • Entering an area is forbidden during some parts of the year, like mating season

  • It can increase productivity in the area, develop more mature species (which lay more eggs) and increase species density

  • It protects the coral reef environment in the area

Quotas

• Quotas are regulations set by governments concerning how much fishing can take place

• Governments or unions must meet the quota standards:

  • In the EU, Total Allowable Catch (TAC) provides a yearly fishing limit 

  • This creates a fair balance for fishing industries, reducing competition and oversupply

• Quotas use scientific information and advice to create and enforce fishing regulations 

• Some disputes may arise from transferring quotas between nations and individual people

• Quotas are a good sustainable method to combat overfishing